The present invention relates to a spring supply device and, more particularly, to a pneumatically operated device for supplying helical wire compression springs in sequence to an output conduit such that the springs may then be conveyed to a remote assembly station.
Helical wire coil compression springs are typically purchased in bulk by manufacturers for use in assembling numerous types of products. The springs are supplied to the manufacturer in containers containing hundreds or even thousands of such springs. The springs in the containers are jumbled and a number of the springs may be tangled or interlocked. It will be appreciated that automatically providing the springs in sequence to a supply conduit for transport to a dispensing device at an assembly station presents a significant problem.
One approach to this problem has been to place the springs in a container having an air inlet in its bottom and a spring outlet opening in its top which communicates with the supply conduit. Air is supplied under pressure to the air inlet and agitates the mass of springs in the container, causing them to move in a random fashion. The spring outlet opening in the top of the container has a diameter only slightly larger than the diameter of the helical coil springs. The random motion of the springs cause various ones of them to enter the outlet opening. Air leaving the chamber through the outlet opening transports the springs to the supply conduit. In the operation of such a device, it is common that a first spring will enter the spring outlet opening only partially and will thereafter be precluded from further movement out of the chamber by a second spring which is interlocked or tangled with the bottom of the first spring. As a consequence, the spring outlet opening will become clogged and further supply of springs to the output conduit will be prevented.
In one prior art device, such clogging is periodically cleared by reversing the direction of air flow. A short pulse of air is forced down the spring outlet opening and into the chamber to dislodge the spring or springs blocking the spring outlet opening. When the springs are tightly wedged in the opening, however, such a pulse of air may not be sufficient to clear the opening, since the springs are formed of thin wire material and offer little air resistance.
Accordingly, it is seen that there is a need for a spring detangler and feeder device in which blockage of the spring outlet opening may be more efficiently cleared.